Modern humans, ancestors share ears

Our early ancestors possessed inner-ear bones similar to those of modern humans, a finding that
researchers say suggests that hearing sensitivity is one of the oldest features of human
evolution.

Such changes could have had a profound effect not only on what these hominins could hear but
also on how they communicated.

Paleoanthropologists from Binghamton University in New York analyzed the tiny middle-ear bones
of
Paranthropus robustus (which lived 1.8 million years ago) and
Australopithecus africanus (3.3 million to 2.1 million years ago). While some of the bones
were similar to those in chimpanzees, both specimens had a malleus, the hammerlike bone attached to
the eardrum, that resembled that of modern humans.

“That implies it is something they inherited from their last common ancestor,” which was the
chimpanzee, “meaning it probably occurred fairly early in the human evolutionary line,” said Rolf
M. Quam, an assistant professor of anthropology at Binghamton. “This may have been one of the
earliest human features to show up.” The research was published last week in
Proceedings of the National Academy of Sciences.

Oyster shells play antacid for the oceans

Like ocean waters around the world, Chesapeake Bay has become more and more acidic as a result
of rising levels of carbon dioxide in the atmosphere. By studying oyster populations in relation to
acidity levels, a team of researchers has concluded that oysters — particularly their shells — can
play a significant role in reducing that acidity.

“Oyster shells are made out of calcium carbonate, so they’re sort of like an antacid pill,” said
George Waldbusser, an assistant professor of earth, ocean and atmospheric sciences at Oregon State
and an author of the study, which appears in the journal
Ecology.